J18.1 Lobar pneumonia, unspecified organism

Billable ICD-10-CM code, FY2026. Acts as a Major Complication or Comorbidity (MCC) as a secondary diagnosis.

Applies from J18 Pneumonia, unspecified organism

Excludes1 (never code together)

• congenital pneumonia (P23.0)
• drug-induced interstitial lung disorder (J70.2-J70.4)
• interstitial pneumonia NOS (J84.9)
• neonatal aspiration pneumonia (P24.-)
• pneumonitis due to fumes and vapors (J68.0)
• usual interstitial pneumonia (J84.178)

Excludes2 (not included here)

• abscess of lung with pneumonia (J85.1)
• aspiration pneumonia due to anesthesia during labor and delivery (O74.0)
• aspiration pneumonia due to anesthesia during pregnancy (O29)
• aspiration pneumonia due to anesthesia during puerperium (O89.0)
• aspiration pneumonia due to solids and liquids (J69.-)
• aspiration pneumonia NOS (J69.0)
• lipid pneumonia (J69.1)
• pneumonitis due to external agents (J67-J70)

Code first

• , if applicable, associated influenza (J09.X1, J10.0-, J11.0-)

Code also

• , if applicable, any associated condition such as:
• aspiration pneumonia (J69.-)

Risk adjustment (HCC)

• CMS-HCC V22: HCC 115 — Pneumococcal Pneumonia, Empyema, Lung Abscess
• ESRD V24: HCC 115

MS-DRG index

Defines the logic of DRG(s) 193-195 in MDC 04.

Approximate ICD-9-CM (GEMs)

• 481 Pneumococcal pneumonia [Streptococcus pneumoniae pneumonia] (approximate)

Code annotations containing back-references to J18.1

Back-references to J18.1

• Type 1 Excludes: J13 Pneumonia due to Streptococcus pneumoniae ("lobar pneumonia, unspecified organism (J18.1)")

Back-references to J18

• Code Also: D81.82 Activated Phosphoinositide 3-kinase Delta Syndrome [APDS] ("pneumonia (J12-J18)")
• Use Additional: J95.89 Other postprocedural complications and disorders of respiratory system, not elsewhere classified ("bacterial or viral pneumonia (J12-J18)")

Diagnosis Index entries for J18.1

• Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved) › lobar (disseminated) (double) (interstitial)

Nearby codes

• J18 Pneumonia, unspecified organism
• J18.0 Bronchopneumonia, unspecified organism
• J18.1 Lobar pneumonia, unspecified organism (this code)
• J18.2 Hypostatic pneumonia, unspecified organism
• J18.8 Other pneumonia, unspecified organism
• J18.9 Pneumonia, unspecified organism